Coupling arrangement between a trailer and a pulling vehicle

ABSTRACT

A coupling arrangement between a trailer and a pulling vehicle wherein the pulling vehicle comprises first coupling plane on which the corresponding second coupling plane of said trailer is placed for obtaining locked coupling, said planes having low friction surfaces allowing said second plane to rotate on said first plane, said planes further being locked to each other by a vertical pin fixed to said second coupling plane wherein the first coupling plane comprises an open groove for said pin to get the locking position in the end of said groove, said coupling arrangement further comprising: a movable locking part fixed to said second plane and being able by means of a spring to move into the groove of said first coupling plane when said planes are rotating in relation to each other, wherein said locking part locating in said groove is locking said planes unrotatable, and for turning the steering wheels of said trailer said second coupling plane is arranged to rotate on said first coupling plane, and by means of turning angle of said second coupling plane or of a vertical axle fixed thereto, the wheels of said trailer is turned.

FIELD OF THE INVENTION

[0001] The invention relates to a coupling arrangement between a trailer and a pulling vehicle wherein said invention will noticeable improve the coupling operation when the pulling vehicle is driven to that kind of coupling which comprises steering arrangement from the coupling to trailer wheels. Said vehicle can be driven for the coupling of the trailer from all possible directions when using the arrangement according to this invention.

BACKGROUND OF THE INVENTION

[0002] The earlier known trailer coupling where turning of trailer wheels have been combined with the coupling is carried out so that the pulling vehicle has to be driven into the coupling in very accurate direction so that the locking part fixed to the trailer coupling will meet the groove of the coupling plane in the pulling vehicle. So the driving of the pulling vehicle into the coupling has to be done just in the same direction as the pulling vehicle has been discoupled.

SUMMARY OF THE INVENTION

[0003] By means of the coupling arrangement according to this invention a great improvement is achieved and characteristic for this invention is what is claimed in the following claims.

[0004] A remarkable advantage is obtained when the pulling vehicle can be driven into coupling in all possible directions and the coupling can be locked and steering for trailer wheels also is transmitted from said coupling. If the driving direction differs from the previous discoupling direction, the movable locking part will move into the groove after a little curved drive of the pulling vehicle. When the locking part thus automatically has moved into the groove the turning of the trailer wheels begins to operate steered by the coupling arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] In the following the invention is explained by referring the enclosed drawings, wherein:

[0006]FIG. 1 is a side view of a coupling arrangement.

[0007]FIG. 2 shows a locking part seen from below.

[0008]FIG. 3 is a side view of the locking part.

[0009]FIG. 4 is a top view of the coupling plane in the vehicle.

[0010]FIG. 5 is a side view of an alternative coupling arrangement.

[0011]FIG. 6 shows a locking part seen from below.

[0012]FIG. 7 is a top view of a drive into coupling.

DETAILED DESCRIPTION OF THE INVENTION

[0013] In the FIG. 1 there is shown a coupling arrangement where first coupling plane 12 is locating on the vehicle frame and second coupling plane 5 is locating in the end of the trailer frame, under said frame. A vertical pin 2 is fixed to the second coupling plane 5 said pin extending below the plane 5 and above said plane. The plane 5 and the pin 2 are rotatable mounted in relation to the trailer frame 1 fixed tube 4 and gliding flange 6,7,8.

[0014] A movable locking part 9 locates under the plane 5, said part being able, according to FIGS. 2 and 3, to move horizontally towards and away from the pin 2. The part 9 can move a distance “a” against the spring 10 steered by a pin 11. The distance “a” can be elected

[0015] so long that the part 9 can move away from the pin 2 so far that the first plane 12 can freely rotate in relation to second plane 5 when the pin 2 is locked in its seat 22 in the first plane 12. (this solution not shown) In this case the pulling vehicle can be driven into coupling from all possible directions.

[0016] so long that accurate driving direction is not needed for the pulling vehicle when driving it into coupling, but it is needed that the part 9 meets the groove 23. (FIG. 4) After locking of the pin 2 into the seat 22 and then driving a curved distance by the vehicle and trailer, the spring 10 will push the part 9 into its final place 25 in the groove 23.

[0017] In the FIGS. 5 and 6 there are shown an alternative locking part solution where a cavity 13 has been formed in the second coupling plane 5 for the part 16. The part 16 can move in the vertical direction against a spring 15 steered by a pin 14.

[0018] When driving the pulling vehicle into the coupling the first coupling plane 12 by means of its inclined portion 24 lifts the locking part 16 up against the spring 15. This lifting occurs in all driving directions of the vehicle except in the case wherein the locking part 16 locates in the line of the groove 23. In that case the driving direction was just correct and the locking part 16 will move into its final place 25.

[0019] If the first coupling plane 12 has lifted the part 16 up so the locking, i.e. the part 16 has fallen down into the groove 23, has to be secured by driving with the pulling vehicle a short curved route so that the coupling planes 12 and 5 will have sufficient mutual rotation. A curved driving will secure that the part 16 can fall down into the groove 23.

[0020]FIG. 7 shows a pulling vehicle 17 and the first coupling plane 23 on the vehicle frame. A trailer comprises a frame 1, a work machine, as a brush device 19 fixed to the frame and a coupling arrangement according to this invention mounted in the end of the frame 1. Coupling arrangement is the same as presented in the FIGS. 1-4. In the upper end of the pin 2 there is an arm 3 fixed to said pin and a steering mechanism 18 between trailer wheels and said arm. The driving direction of the vehicle 17 is not correct, in FIG. 7, wherein the part 9 will not meet the groove 23. The part 9 has to be retreated or new driving line has to be elected.

[0021] In the FIG. 1 there is moreover presented an alternative system for steering the trailer wheels by means of information sensored from the coupling. On the frame 1 there is a control unit 21 for observing the turning angle of the pin 2. A sensor means 20 has been fixed round the pin 2. When the part 9 or 16 has been placed into its final place in the groove 23 the control unit 21 by means of sensor 20 begins observe the angle of the vertical axle, as pin 2 in relation to the frame 1 line, for example. The observed angle information is whole time sent to the unit near trailer wheels (not shown) and there is for example a hydraulic system with cylinder mounted, said system turning the wheels according to angle information received from the unit 21. The mechanism 18 is not needed in this case. The sensor 20 can be fixed also to the second coupling plane 5, wherein no vertical axle, as the pin 2, is needed above the plane 5, it is needed only below said plane.

[0022] The locking part 9 or 16 can move into the groove 23 by means of horizontal or vertical motion or from whichever direction due to the used solution according to the invention. 

I claim:
 1. A coupling arrangement between a trailer and a pulling vehicle wherein the pulling vehicle comprises first coupling plane on which the corresponding second coupling plane of said trailer is placed for obtaining locked coupling, said planes having low friction surfaces allowing said second plane to rotate on said first plane, said planes further being locked to each other by a vertical pin fixed to said second coupling plane wherein the first coupling plane comprises an open groove for said pin to get the locking position in the end of said groove, said coupling arrangement further comprising: a movable locking part fixed to said second plane and being able by means of a spring to move into the groove of said first coupling plane when said planes are rotating in relation to each other, wherein said locking part locating in said groove is locking said planes unrotatable, and for turning the steering wheels of said trailer said second coupling plane is arranged to rotate on said first coupling plane, and by means of turning angle of said second coupling plane or of a vertical axle fixed thereto, the wheels of said trailer is turned.
 2. A coupling arrangement according to claim 1 wherein the locking part is moving into said groove in the horizontal direction.
 3. A coupling arrangement according to claim 1 wherein the locking part is moving into said groove in the vertical direction.
 4. A coupling arrangement according to claim 1 wherein by moving or retreating of the locking part the coupling and the locking of the vertical locking pin to said first coupling plane can be carried out in any location angles of said locking part in relation to the groove of said first coupling plane.
 5. A coupling arrangement according to claim 1 wherein the locking part is moving into the groove from whichever direction. 